Find a way that travels from dot to dot, horizontally and vertically only, and ends where it began, never touching or crossing itself. The numbers indicate the number of adjacent corners where the path bends 90 degrees.

Draw a circular path on the grid line. Not all grid points must be used. But all the red and blue dots are on the path. The lengths of the edges of the path are 1 or 2. On a blue circle meet two lines of equal length each other with a right angle. At red circles two lines of different lengths meet each other with a right angle.

Find a way that travels from dot to dot, horizontally and vertically only, and ends where it began, never touching or crossing itself. The numbers that have been placed in the diagram tell you how many of the four sides of the "square" it lies in are used for the path. (The path doesn't necesserily need to touch all of the dots.)